In semiconductor technologies, image sensors are used for sensing a volume of exposed light projected towards the semiconductor substrate. Backside-illuminated photodetectors are an example of an image sensor for sensing a volume of radiation (e.g., light) projected towards the back surface of a semiconductor substrate. The photodetectors may be formed on the front side of the substrate, the substrate being thin enough to allow the radiation incident on the back surface of the substrate to reach the photodetectors.